JP2012232438A - Light transmissive sheet material, and sun shade using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light transmissive sheet material that permits transmission of a sufficient amount of light, achieves a high blinding effect, and obtains high light blocking effect and heat shielding effect as well as high visibility.SOLUTION: In the sheet material, a metal layer is provided on one surface of a woven knitted good in which a cover factor is 500-4,000 using a synthetic fabric with a total fineness of 10-330 dtex, and the metal layer is not on the opposite surface. The visible light transmittance from the one surface to the opposite surface of the sheet material is 5-50%, and the visible light reflectance on the opposite surface is 30% or less.

Description

  The present invention relates to a light-transmitting woven / knitted sheet material used for blinds and shades installed indoors, in vehicles such as automobiles and trains.

  Blinds and shades are installed to shield outside light that enters the room or the interior of the vehicle. As materials for the light shielding member, various materials such as metal plates, resin plates, and fabrics are used according to applications. . Among them, fabrics made of woven fabrics and knitted fabrics can be used as interior designs, and various types of fabrics have been proposed. For example, in Patent Document 1, a knitted structure between a front and a back is knitted with a chain knitting yarn and an insertion yarn in a separated state, and another yarn is slanted between the front and the back in an oblique direction. A blind knitted fabric having a knitted portion is described. In Patent Document 2, as a heat-shielding sheet that can be used as a raw material sheet for curtains and blinds, a light-reflective transparent metal film is formed by sputtering on the surface of a cloth obtained by knitting and weaving. There is a method to apply. Furthermore, in Patent Document 3, a screen door in which a filament having a diameter of 50 to 100 μm is plain-woven as an amide net with an open feeling that can improve the air permeability during use and can more clearly see the scenery outside the room. Internet has also been proposed.

Japanese Utility Model Publication No. 3-128680 JP 2006-174978 A JP 2006-183382 A

  In the above-mentioned Patent Document 1, when the knitted fabric is viewed from a direction parallel to the knitted portion in the oblique direction, the gap between the front and the back can be visually recognized as a gap, and the knitted fabric is shielded by the knitted portion in the front direction or the oblique direction. Therefore, when used as an in-vehicle sunshade, it is convenient to protect visible light shielding and privacy, but the visibility when looking outside the vehicle from inside the vehicle is not considered at all. Therefore, it was not suitable for use on the side glass side or rear glass side of the vehicle. In Patent Document 2, the heat shielding property is improved by performing the sputtering process, but the transmittance of visible light is not considered, and the visibility through the curtain is poor. Furthermore, since the fabric of Patent Document 3 is intended for use in screen doors, the visibility is good, but the light shielding property is low.

  An object of the present invention is to provide a light-transmitting sheet material that can transmit a sufficient amount of light and that has a high blind effect and at the same time has high visibility.

The light-transmitting sheet material is intended for use in sunshades and blinds used in vehicles such as automobiles. Therefore, it is required to satisfy both conflicting performances such as improving the visibility of the driver's seat from the outside. Furthermore, there is a demand for a thin and light product that can be stored in a lightweight and compact manner.
As a result of intensive studies on the structure of the light-transmitting sheet for satisfying these light characteristics, the present inventors solved this problem by applying a metal vapor deposition layer only to one side of a woven or knitted fabric having characteristics within a specific range. It came to do.

  Means for solving the above-mentioned problem, that is, the configuration of the present invention is such that a metal layer is provided on one side of a woven or knitted fabric having a cover factor of 500 to 4000 using synthetic fibers having a total fineness of 10 to 330 dtex, and the opposite side. Is a sheet without a metal layer, the visible light transmittance from the one side of the sheet material to the opposite surface is 5 to 50%, and the visible light reflectance of the opposite surface is 30% or less Is a light-transmitting sheet material.

  It is preferable that the visible light reflectance of the surface provided with the metal layer of the light transmissive sheet material is 20 to 80%.

It is preferable that the thickness of the woven or knitted fabric of the light-transmitting sheet material is 0.1 to 2.0 mm and the basis weight is 20 to 200 g / m ² .

  It is preferable that the woven or knitted fabric forming the light-transmitting sheet material is colored so that the lightness L value expressed using a spectrocolorimeter specified in the text is 8 to 30.

  The metal layer of the light-transmitting sheet material is preferably made of at least one metal selected from the group consisting of aluminum, stainless steel, and titanium, and is formed by physical vapor deposition.

  It can be preferably used as a vehicle-mounted sunshade made of the above-described light-transmitting sheet material.

  According to the present invention, visible light can be reflected preferably by 25 to 80% on the surface of the metal layer provided on one side by the above configuration, and when combined with the light component absorbed by the fabric itself, high light shielding properties and heat shielding properties are achieved. Can be obtained. In addition, while maintaining a certain level of transparency, the visible light reflectivity of the opposite surface of the sheet material can be kept low, so that high visibility can be obtained, high light shielding properties and high heat shielding properties and high visibility. It becomes possible to provide a light-transmitting sheet having both characteristics.

It is a figure which shows the outline of the standard light source device used for the visibility evaluation outside the vehicle of this invention.

  Hereinafter, the present invention will be described in detail based on specific examples. However, the present invention is not limited to these examples, and may be implemented with modifications within a scope that conforms to the purpose described above and below. Are all possible and are within the scope of the present invention.

In the present invention, it is preferable to use a synthetic fiber having a total fineness of 10 to 330 dtex.
Examples of synthetic fibers include polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, and polyolefin fibers such as polypropylene and polyethylene. A synthetic fiber may be used independently and may be used in combination of 2 or more type. Among these, polyester fibers, polyamide fibers, and polyolefin fibers are preferably used for vapor deposition because of their low hygroscopicity. Polyester fibers are particularly preferable. On the other hand, when natural fibers, regenerated fibers, and semi-synthetic fibers are used, it is difficult to evacuate during the physical vapor deposition process due to the hygroscopicity of the material, resulting in inability to vapor deposit and poor adhesion of the metal thin film. It will be enough. However, it can be mixed to the extent that vacuuming is not significantly hindered.

  The total fineness of the synthetic fiber is preferably 10 to 330 dtex. Preferably it is 15-250 dtex. More preferably, it is 20-190 dtex. Here, when the total fineness is less than 10 dtex, the visible light permeability of the woven or knitted fabric becomes too high, and the blind effect tends to be lowered. On the other hand, if it exceeds 330 dtex, it becomes thick knitted knitted fabric, which tends to be difficult to use for in-vehicle sunshades.

  In addition, as a form of the fiber yarn, a filament (raw yarn) or a long fiber subjected to yarn processing such as false twisting or taslan processing can be used. Further, different long fibers may be combined to form a yarn. Examples of the composite form include FTY (filament twisted yarn), single (double) covering yarn, air covered yarn, false twisted composite yarn mixed simultaneously with false twisting, and the like. Further, short fibers may be spun and used, or a short composite spun yarn obtained by combining short fibers and short fibers or short fibers and long fibers may be used. Examples of the composite form of short fibers include blended yarn, twisted yarn, core spun yarn, and pliers. The form of these fiber yarns may be appropriately selected and used from the viewpoints of design properties as sunshades and blinds and visible light transmission performance.

  The cover factor of the woven or knitted fabric in the present invention is 500 to 4000, preferably 800 to 2000, and particularly preferably 800 to 1800. The cover factor of the present invention is obtained as follows.

[Cover factor]
(1) Woven fabric: CF = (√thickness of warp (decitex) + √thickness of weft (decitex)) × (warp density + weft density)
(2) Warp knitting: CF = (√thickness of front side yarn (decitex) + √thickness of back side yarn (decitex) + √thickness of pattern yarn or insertion yarn (decitex)) × (warp density + weft density)
(3) Circular knitting: CF = (2 × √thickness of thread (decitex)) × (warp density + weft density)
* However, when using multiple yarns in circular knitting, for example, when using yarn A and yarn B,
(2 × (√thickness of thread A (decitex) + √thickness of thread B (decitex))) × (warp density + weft density). The density here refers to the number of yarns or stitches per 2.54 cm.

  The thickness of the woven or knitted fabric in the present invention is preferably 0.1 to 2.0 mm. More preferably, it is 0.2 to 1.2 mm, and particularly preferably 0.2 to 0.9 mm. Here, when the thickness of the woven or knitted fabric is less than 0.1 mm, the handleability when the product is made too thin to make a product is bad, and when the thickness exceeds 2.0 mm, the thinness intended in the present invention is used. This is not preferable because it falls outside the category of the fabric.

The basis weight of the woven or knitted fabric in the present invention is preferably ²⁰ to 200 g / m ² . More preferably, it is good to set it as 30-150 g / m < ² >. Here, when the basis weight of the woven or knitted fabric is less than 20 g / m ² , it is not preferable because the density becomes rough and gaps increase, or the yarn is too thin and easily penetrated. On the other hand, it exceeds 200 g / m ^2. In this case, the dough is thick, and the light and compact product intended by the present invention cannot be obtained.

The woven or knitted fabric forming the sheet material of the present invention is not limited to a woven fabric or a knitted fabric as long as the cover factor, thickness, and basis weight are satisfied. In the case of a woven fabric, a general woven fabric structure such as a plain woven fabric, a twill woven fabric, a satin weaving fabric, or a jacquard woven fabric combining these can be appropriately selected. It is possible to use a strong twisted yarn and a textured fabric such as a georgette, or a tangled structure such as wrinkles or folds.
In the case of a knitted fabric, any of warp knitting, weft knitting (round knitting), lace and the like may be used. In the case of weft knitting, it can be used without any particular limitation, such as a circular knitted fabric, a tentacle reversible structure, a milling structure, an interlock structure, a reversible structure, and other changing structures.
In the case of warp knitting, any warp knitting such as tricot knitting, Raschel knitting, and Milanese knitting may be used. As the organization, a half organization, a back half organization, a quinz code organization, a satin organization, a satin net organization, a power net organization, a triconet organization, and other change organizations can be used. A structure such as a power net structure is preferably used because a fine gap is formed in the knitted fabric to easily control the transmittance of visible light and the balance of the stretchability of the background.

  In the present invention, as a method of controlling the visible light transmittance from the surface provided with the metal layer of the sheet material to the surface side not provided with the metal layer to 5 to 50%, a method of controlling with the density of the woven or knitted fabric, A method of creating a gap in the tissue by a handle can be used, or a combination may be used. When controlling by density, warp density (the number of wales) and latitude density (course) may be appropriately set so that the transmittance is in a desired range. At this time, the transmittance may be controlled by utilizing the fact that a gap due to the fineness difference is formed in the place where the fine yarn is used by using a mixture of the fine yarn and the thin yarn alternately. Further, the gap may be formed by a method such as making empty feathers or mixing and dissolving a readily soluble fiber and then dissolving and removing only the easily soluble fiber.

  As a method of creating a gap in the structure with the above-described pattern, there is a method of creating a gap by knit or tack in the case of circular knitting. In warp knitting, it is preferable to use a mesh or a net by mixing chain stitches with other swing structures. It is also possible to dissolve or leave the pattern portion by a printing technique such as opal processing. However, care should be taken when selecting a handle because the ground portion may adversely affect the visibility if a gap is made with a very large handle. In the woven or knitted fabric of the present invention, elastic yarn may be woven (knitted) or inserted in order to enhance stretchability. Examples of the elastic yarn include latent crimped yarn by spandex or a composite spinning method, and cross-linked polyolefin. You may use the composite fiber which mixed the elastic yarn and the other fiber.

  The L value of the surface having no metal layer of the woven or knitted fabric of the present invention is preferably 8-30. When the L value is controlled within this range, the visibility when viewed through the surface of the woven or knitted fabric opposite to the surface on which the metal layer is provided can be further enhanced. Here, if the L value is greater than 30, the visible light reflectance of this surface increases, and the visibility decreases. A lower L value is better, but it is technically difficult to make it lower than 8 using general-purpose synthetic fibers. Preferably, it is 25 or less, more preferably 20 or less.

  In order to make it the range of the said L value, you may dye | stain with the density | concentration more than a medium dark color by the post dyeing after making yarn dyeing or knitting. Moreover, you may use the thread | yarn which knead | mixed the color material into the thread | yarn beforehand and colored as an original thread | yarn.

  The L value can be lowered by kneading a color material such as carbon black into a synthetic fiber as an original yarn. The carbon black content in the case of kneading carbon black to obtain a black original yarn is preferably 1.0% by mass or more, but from the viewpoint of stabilizing the yarn-making property and the high-order processing process passability, 5.0% by mass or less. Is preferred. A more preferable content is 1.5 to 4.0% by mass.

  In the present invention, it is necessary to form a metal layer only on one side of the substrate after the fabric or knitted fabric is used as the substrate. Examples of the metal for forming the metal layer include metals that well reflect visible light, such as aluminum, stainless steel, titanium, gold, silver, copper, tin, platinum, chromium, nickel, or alloys thereof. A metal layer having a metallic luster is preferably formed, and the reflectivity of the metal in visible light having a wavelength of 650 nm is 90% or more. More preferably, the metal having a high reflectance at all visible wavelengths is a metal having a reflectance of 90% or more at both wavelengths of 450 nm and 650 nm. More preferable examples of the metal include aluminum, titanium, silver, platinum, and stainless steel. Aluminum, titanium, and stainless steel are more preferable from the viewpoint of corrosivity and cost. When the reflectance of visible light having a wavelength of 650 nm is less than 90%, the light shielding property of the sheet is lowered when the cover factor of the sheet is lowered in order to obtain in-vehicle visibility as in the present invention. The reflectance of the metal layer is listed in, for example, the Physical Data Dictionary (Asakura Shoten, 2006).

  These metals may be used alone or in combination of two or more. In the case of using the physical vapor deposition method, aluminum alone or an alloy in which aluminum and other metals are combined is preferable in consideration of cost, safety, easiness of vapor deposition processing, and the like. Furthermore, when it is set as an alloy, it can also be set as the inclination structure | tissue which changed the alloy composition ratio in the thickness direction of the metal layer.

  In the present invention, the metal layer is preferably formed by physical vapor deposition. By adopting the physical vapor deposition method, it is possible to suppress the sheet from becoming hard or thick. Further, since the gap between yarns is not closed or narrowed, the metal layer can be formed efficiently without deteriorating the function of the metal layer without deteriorating the light transmittance. Examples of the physical vapor deposition include evaporation methods such as vacuum vapor deposition, molecular beam vapor deposition, ion plating, and ion beam vapor deposition, and sputtering. Among these, the evaporation system method is more preferable because of good production efficiency.

  Since the metal layer formed by physical vapor deposition can reduce the thickness of the layer to the nano level, it is suitable for maintaining the light transmittance of the sheet material of the present invention. Since the fiber does not form a flat surface like a film, it is difficult to measure the actual layer thickness, but on average, it is preferably 10 nm or more, more preferably 30 nm or more, and 500 nm or less. It is preferable that it is 200 nm or less. If the thickness is too thin, the infrared reflection performance and the resulting heat retention effect and durability in actual use may be insufficient. On the other hand, when the thickness is too thick, the texture and air permeability of the base nonwoven fabric are deteriorated, and a phenomenon such as metal discoloration is likely to occur. The thickness of the metal layer was determined by measuring the film deposited by the transmission method using a Macbeth densitometer TR-927 manufactured by Macbeth after the polyester film was connected before and after the woven or knitted fabric. The thickness of the metal layer of the deposited product can be estimated by converting the OD (optical density) value.

  In the present invention, the metal layer may be formed by a plating process such as an electroless plating method, but the plating method devises only one side. Then, a thick metal film in which a part of the metal has penetrated is also formed inside the base material, and the light reflection and transmission characteristics tend to be deteriorated.

  The visible light transmittance of the surface provided with the metal layer of the light transmissive sheet material of the present invention is 5 to 50%, preferably 7 to 40%, and more preferably 9 to 30%. The visible light transmittance is an index indicating the effect of shielding visible light as the basic performance of the sunshade. When the visible light transmittance exceeds 50%, the effect as the sunshade becomes unsatisfactory. If it is less than 5%, it can be used as a sunshade, but it is difficult to obtain visibility outside the vehicle.

  Further, the visible light reflectance of the surface of the light transmissive sheet material of the present invention on which the metal layer is not provided needs to be 30% or less, more preferably 20% or less. The reason for this is that, for example, when used in a car, the visibility of the scenery outside the car is further improved if the reflection inside the car is reduced.

  The visible light reflectance of the surface provided with the metal layer of the light transmissive sheet is preferably 20 to 80%, more preferably 25 to 70%. In order to make the sunshade highly visible, it is necessary to make the seat structure more transparent than the conventional sunshade, but maintaining the effect of making the inside of the vehicle difficult to see from outside the vehicle by making the visible light reflectance within this range can do. When the visible light reflectance is less than 20%, the interior of the vehicle becomes easy to see. On the other hand, if it exceeds 80%, the transparency of the knitted or knitted fabric to be used becomes low, and the visibility outside the vehicle tends to decrease.

  The present invention will be described below based on examples. In addition, the measuring method used in the Example is as follows.

(Lightness L value of woven or knitted fabric)
Using a spectrocolorimeter (manufactured by Minolta: CM-3700), eight woven and knitted fabrics were stacked, and the L value was measured. As measurement conditions, the L-value light source was D65 and the viewing angle was 10 degrees.

(Visible light reflectance)
The reflectance in the wavelength range of 380 to 780 nm was measured with a spectrophotometer (Shimadzu UV-3100PC). The integrating sphere attachment device attached to the photometer was ISR-3100 integrating sphere inner diameter 60 mmφ, and the standard white plate was barium sulfate. The measurement was performed by attaching the measurement surface of the sheet to the light source side of the spectrophotometer at the mounting position for measuring the reflectance of the integrating sphere. Three samples were prepared from the same sample and evaluated by the average value of the three measurement data.

(Visible light transmittance)
The transmittance in the wavelength region of 380 nm to 780 nm was measured with a spectrophotometer (Shimadzu UV-3100PC). The integrating sphere attachment device attached to the photometer was ISR-3100 integrating sphere inner diameter 60 mmφ, and the standard white plate was barium sulfate. In order to attach the sample to the sample holder attached to the integrating sphere, two pieces of cardboard were prepared by cutting out a rectangular slit of length 2.5 cm × width 1 cm in the center of a rectangle 6 cm × width 3 cm. The sheet sample was cut into a length of 6 cm and a width of 3 cm, and sandwiched between two prepared cardboard sheets, and then attached to the sample holder. The measurement was performed with the sample holder attached to the attachment position for measuring transmittance on the incident light side of the integrating sphere and the measurement surface of the sheet facing the light source side of the spectrophotometer. Note that the purpose of using the cardboard from which the slit is cut is to prevent the measurement value from degrading due to wrinkling of the sample. Three samples were prepared from the same sample and evaluated by the average value of the three measurement data.

(Visibility evaluation outside and inside the vehicle)
Visibility (image clarity) was evaluated by the following method as an indicator of visibility outside and inside the vehicle.
Two pieces of cardboard prepared by cutting out a rectangular slit of 10 cm in length and 10 cm in width at the center of a square of 12 cm in length and 12 cm in width were prepared. A sheet sample was taken to a size of 12 cm × 12 cm. A sheet was sandwiched between the two cardboards so that there were no wrinkles or sagging, and fixed with double-sided tape to obtain a measurement sample. FIG. 1 shows a schematic diagram of a standard light source device.

A gray scale for JIS dyeing fastness test is erected on the center of the back wall surface of the standard light source device, the measurement sample is fixed at a position 20 cm in front of the gray scale surface in the vertical direction, and the gray scale is further looked into from the front surface 20 cm from the measurement sample. Whether or not a gray scale white (black) / gray boundary line can be visually recognized was evaluated as visibility. The grade is judged by the lowest gray scale series that can be visually recognized. In the present invention, it is determined that the visibility outside the vehicle is higher than the third grade and the visibility inside the vehicle is lower than the second grade, respectively.
When evaluating the in-vehicle visibility, the surface of the measurement sample having the metal layer is directed to the measurer side. The gray scale is used for discoloration. The inside of the car is so good that it is difficult to see, so it is good: 1st grade> 5th grade: poor. When evaluating the visibility outside the vehicle, the surface having the metal layer is directed to the gray scale. Gray scale is used for contamination. Since the outside of the vehicle is easy to see, it is good: 5th grade> 1st grade: bad.
Standard light source device: Verisphere CAC60 (Apparatus for Standard Visual of Color by Reflection & Transmission) manufactured by Leslie Hubble Limited.
Light source: Artificial Daylight BS950PEL, F20T12 / D65 (manufactured by Verify)

(Sensory evaluation)
An in-vehicle sunshade was created using the sheets of the examples and comparative examples. The sheet was sampled in a size of 50 cm in length and 50 cm in width, and sewed as a hem having a width of 2 cm and black cotton fabric (poplin) on the four sides. Further, in order to obtain formability, the wire was attached to the sheet together with the hem so that the wire was wrapped around the hem along the four sides. Finally, suction cups were attached to the four corners of the sewn sheet so that they could be attached to the glass surface. Using this sunshade, it is attached to the window glass on the side of the passenger's seat of the Toyota Prius (ZVW30) at noon on a clear day, providing light shielding from the driver's seat, visibility inside the vehicle, and visibility outside the vehicle. A three-stage evaluation of x was performed.
Light-shielding property: good light-shielding ○> slightly bad Δ> bad X
Visibility in the car: Difficult to see inside the car ○> Slightly visible Δ> Good inside the car x
Visibility outside the vehicle: The outside of the vehicle can be seen well.

Example 1
[Code Tengu]
78 dtex / 216 filament round cross-section semi-polyester (polyethylene terephthalate) yarn (manufactured by Toyobo Co., Ltd., “Silflora X (R)” and 33 dtex / 12 filament round cross-section semi-dal polyester yarn (manufactured by Toyobo Co., Ltd.) Were knitted with cord tense knitting alternately using a single circular knitting machine (manufactured by Fukuhara) with a 34 inch caliber. ), Followed by dehydration and reversal, followed by a pre-set treatment at 190 ° C. for 1 minute using a pinoter made of Hirano Tech Seed, and then using the same liquid dyeing machine, And then washed in gray.
<Dyeing prescription>
Black dye (Dianix Black BG-FS200) 1.5% owf
Disper TL 1.0g / L
60% acetic acid 0.5g / L
Bath ratio = 1: 13
Dyeing temperature 135 ° C x 45 minutes <Reduction cleaning>
Hydrosulfite 2g / L
Soda ash 2g / L
Bath ratio = 1: 13
A treatment temperature of 80 ° C. × 20 minutes was followed by washing and drying.
Thereafter, using the same liquid dyeing machine, black was dyed and washed with the following formulation. Finally, final setting was performed with a pin tenter at 170 ° C. for 1 minute. This knitted fabric was set in a vacuum vapor deposition machine, and metal aluminum was vapor-deposited on the surface of the knitted fabric in a vacuum environment to obtain a visible light transmissive sheet. (Vacuum degree: 3.0 × 10 ⁻⁴ Torr, running speed: 100 m / min) OD (optical density) value after deposition of the polyester-based lead film attached to the front and back of the substrate The thickness of the deposited metal aluminum was estimated to be about 60 nm by using the transmission method and converting from the measured value. The results of evaluating this sheet are shown in Table 1.

(Example 2)
[Plain weave]
Black original polyester multifilament (round cross section, 110 dtex, 48 filament) and black original polyester multifilament kneaded with carbon black having an average secondary particle size of 0.05 to 0.50 μm at a content of 3.0% by mass (Circular cross section, 110 dtex, 24 filaments) were twisted with a double twister manufactured by Murata Manufacturing Co., Ltd. so as to have a twist number of 2500 T / m, respectively, thereby producing strong twisted yarns of S twist and Z twist. This black original multifilament 1 strong twisted yarn is used for warp, and the black original multifilament 1 strong twisted yarn and the black original multifilament 2 strong twisted yarn are used alternately as the weft (two S twist yarns and two Z twist yarns, respectively). A plain woven fabric at a warp density of 95 / inch and a weft density of 80 / inch. Next, relaxation was performed with a normal washer and desizing / scouring was performed. It heat-set at 190 degreeC using the pin tenter. The fabric density after setting was 110 / inch and 88 / inch. Aluminum was deposited on this fabric under the same conditions as in Example 1 to obtain a visible light transmissive sheet. The results of evaluating this sheet are shown in Table 1.

(Example 3)
[Power Net]
A semi-dull polyester yarn (Toyobo Co., Ltd., Toyobo Polyester E84T24f-72B) with a round cross section of 84 dtex / 24 filaments is arranged in a half set as the front sheath yarn, and a 155 dtex polyether polyurethane yarn as the back sheath yarn (Toyobo Co., Ltd., ESPAR (registered trademark): clear type) is placed in a half set, and using a 28 gauge Russell knitting machine (made by KARL MAYER), the warp draft of polyurethane yarn is 1.6 times The power net organization was organized under the following conditions. The mixing ratio of the polyester yarn and the polyurethane yarn was 83%: 17%.
Knitting condition Front length 1 10/12/21/23/21/12 Runner 115cm / R
Front height 2 23/21/12/10/12/21 Runner 115 cm / R
Back length 1 11/00/11/00/11/00 Runner 8cm / R
Back length 2 00/11/00/11/00/11 Runner 8 cm / R
Next, the knitted fabric is subjected to continuous scouring (60 ° C. to 95 ° C. × 60 seconds) —preset (190 ° C. × 30 seconds) —dying (liquid flow: disperse dyeing 135 ° C. × 30 minutes) —finishing set (160 ° C. × 30 seconds). The same disperse dye as in Example 1 was changed to a concentration of 5% owf and dyed black. Aluminum was deposited on this knitted fabric under the same conditions as in Example 1 to obtain a visible light transmissive sheet. The results of evaluating this sheet are shown in Table 1.

(Comparative Example 1)
The final set up of the cord sheet of Example 1 was subjected to evaluation without aluminum deposition. The results are shown in Table 1.

(Comparative Example 2)
A cord set of Example 1 that was final set without being dyed black was used for evaluation. The results are shown in Table 1.

(Comparative Example 3)
Polyester multifilament (semi-dal, round cross section, 56dtex, 108 filament) 1 heater false twisted yarn is used for warp and weft, warp density is set to 204 / 2.54cm, and weft density is set to 90 / 2.54cm Then, weaving was performed with a texture (arranged by aligning two warps).
After scouring the obtained dough using an open soaper in accordance with a conventional method, it was preset using a pin tenter at 190 ° C. × 30 seconds, and carried out using a liquid flow dyeing machine (Hisaka Seisakusho: Circular NS). After dyeing black with the same formulation as Example 3, intermediate setting was performed at 180 ° C. for 30 seconds. Then, after calendar processing (processing conditions: cylinder processing, temperature 150 ° C., pressure 2.45 MPa (25 kgf / cm ² ), speed 20 m / min), soft finishing is performed, and the density is 204 in the longitudinal direction. /2.54 cm, 94 in the weft direction / 2.54 cm, a cover factor of 2230, and a basis weight of 85 g / m ² was obtained. The results of evaluating this sheet are shown in Table 1.

(Evaluation considerations)
As can be seen from the evaluation results in Table 1 above, Examples 1 to 3 of the present invention have good outside-vehicle visibility of grades 3-4 to 4-5 and in-vehicle visibility grades of 1 to 1-2. Results were obtained. The light-shielding property evaluated by sensory evaluation was also good. On the other hand, in Comparative Example 1, since the knitted fabric was dyed and the L value was set to 12, the visible light reflectance of the non-metal surface was suppressed to 9%, but a metal layer was provided on one side of the sheet material. The visibility inside the vehicle is grade 4, and the difference from the present invention is greatly increased. Further, in the case of Comparative Example 2, since the knitted fabric is not dyed and no metal layer is provided on one side, the visible light reflectance of the non-metal surface is as high as 45.5%, and the visibility outside the vehicle is It was a second grade, and the difference with the present invention was greatly increased. Furthermore, the light shielding evaluation and the visibility outside the vehicle were not good. Comparative Example 3 had very good light shielding properties, but was not visible at all inside and outside the vehicle.

Since the light-transmitting sheet material of the present invention has high light-shielding properties, heat-shielding properties, and high visibility, if used as an automobile sunshade, the driver can check safety outside the vehicle, and confirm safety such as opening and closing the door. Can be easily. Also, when used in guest rooms such as trains, you can enjoy the scenery outside the vehicle in a comfortable environment by blocking the hot sunlight.

Claims (6)

  A metal layer is provided on one side of a woven or knitted fabric having a cover factor of 500 to 4000 using synthetic fibers having a total fineness of 10 to 330 dtex, and the opposite side is a sheet material without a metal layer, A light-transmitting sheet material, wherein the visible light transmittance from the one surface of the material to the opposite surface is 5 to 50%, and the visible light reflectance of the opposite surface is 30% or less.   The light-transmitting sheet material according to claim 1, wherein the visible light reflectance on one side is 20 to 80%. Woven thickness of knitted fabric 0.1 to 2.0 mm, the light transmitting sheet material according to claim 1 or 2 basis weight is 20 to 200 g / ^{m 2.}   The light-transmitting sheet material according to any one of claims 1 to 3, wherein the woven or knitted fabric is colored so that a lightness L value is 8 to 30 when the color is measured at a viewing angle of 10 degrees with a D65 light source.   The light-transmitting sheet material according to any one of claims 1 to 4, wherein the metal layer is made of at least one metal selected from the group consisting of aluminum, stainless steel, and titanium, and is formed by a physical vapor deposition method. An in-vehicle sunshade comprising the light-transmitting sheet material according to any one of claims 1 to 5, wherein the sunshade is mounted so that a surface provided with a metal layer faces outside the vehicle.

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